Extrusion press



April 19, 1960 P. BILLEN ETAL EXTRUSION PRESS 6 Sheets-Sheet 1 Filed Nov. 27. 1957 WEA/raps 2C? Z3 L Lez?,

H 2 o bra/ Ill )Uuml wr April 19, 1960 P. BILLEN ETAL EXTRUSION PRESS 6 Sheets-Sheet I2 Filed Nov. 27, 1957 INVENTOPS April 19, 1960 P. BILLEN ETAL 2,933,184A

' v ExTRUsIoN PRESS Filed Nov. 27, 1957 6 Sheets-Sheet 3 /NIENTOPS .IQLLen/ Jjlobzc'z/ April 19, 1960 P. BILLEN E'rAL EXTRUSION PRESS 6 Sheets-Sheet 4 Filed Nov. 27, 1957 April 19, 1.960 P. BILLEN ETAL ExTRUsIoN PRESS W 1v1 Am.

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Filed Nov. 27, 1957 April 19, 1960 Filed Nov. 27, 1957 P. BILLEN ET Al.

EXTRUSION PRESS 6 Sheets-Sheet 6 l uw lil-0511@ EXTRUSQN PRESS Peter Billen, Leverkusen-Kuppersteg, and Helmut Rolira, Mlheim (Ruhr), Germany, assignors to Schloeinann Aktiengesellschaft, Dusseldorf, Germany Application November 27, 1957, Serial No. 699,223 Claims priority, application Germany November 2S, 1956 4 Claims. (Cl. 207-3) In, presses for the extrusion of. hollow products, having a displaceable container and a cross-head carrying the press ram, together with a piercing mandrel, the con tainer must be mounted exactly centrally upon the dieholder and the stationary abutment or counter-holder, in order that the piercing of the billet by the mandrel may beV accurately central. Otherwise the production of a uniform extruded product is not possible. The axis of the container must therefore coincide exactly, during the piercing and during extrusion, with Vthe extrusion axis of the press, and particularly with the axis of the mandrel. Theguiding ribs or ledges generally provided for the container usually do not suffice for the requisite centering, even when they are new and `still unworn. Therefore it frequently happens that the container is not mounted exactly centrally upon the die-holder, so that the piercing mandrel meets the billet eccentrically.

The object of this invention is to provide an exactly central introduction of the container into its operative position, and for` this purpose use is made of the fact that the press ram or press plunger and the die or dieholder can in all pressesbe accurately centered in relation to one another.

The invention consists in the feature that the container is rigidly connected with a sliding crossbar arranged behind the cross-head, and that the cross-head and the sliding cross-bar have adjusting surfaces `that can be pressed against one another for the purpose of straightening the position of the sliding cross-bar. ln this way, the container can be accurately adjusted to the cross-head before reaching the extrusion position.

For this purpose the cross-head will preferably be so placed that the adjusting surface of the sliding cross-bar comes into contactwith the adjusting surface of the crosshead only just before the sliding cross-berend the container reachthe extrusion position. The alignment may hel elected in a position in which the container is located only a few millimeters in front of the extrusion position. Upon the still untraversed sliding distance, of a length of only a few millimeters, no appreciable ltransverse displacement of the container is any longer to be feared. Even if complete certainty is desired with respect to this short path, it is possible to advance the cross-head and the container together, with the slidinrY cross-bar, so that then, even on this short travel, the alignment of Vthe sliding cross-bar, together with the container, in relation to the cross-head, is reliably maintained.

The combined advance of the cross-head and the sliding cross-bar upon this last part of their path is facilitated if the displacing forces that can act upon the slidf ing cross-bar are greater than the retractil/e forces that can act upon thecross-head. It is then possible, in hydraulic presses, when moving the container into the ero trusion position, to let the withdrawal means of the crosshead stand under full load, Vand or the container, with the sliding cross-bar, to travel into the working position against the force of the retract-ion means, so that an absolutely iirm contact between the cross-head and the the Sliding cross-bar 21.

Faltanted Apr. 19, 1960 2, sliding cross-bar is obtained, and the alignment of the container is also ensured in the very last part of its sliding movement. i

The invention is applicable not merely to horizontal but also to vertical presses; and it is applicable irrespectively of whether the piercing mandrel is mounted rigidly on the press ram or Whether it is independently slidable in relation to the press ram.

Two embodiments of the invention are shown in the accompanying drawings, in which:

Figure 1 shows in longitudinal sectional elevation a press according to the invention for the extrusion of hollow products;

Figure 2 shows a section on the line ll-II in Figure l;

Figure 3 a section on the line lll-HH in Figure l;

Figure 4 a section on the line IV-IV in Figure l;

Figure 5 a section on the line V-V in Figure l;

' `Figure 6 shows another embodiment in side elevation;

Figure 7 shows this embodiment in longitudinal sectional elevation; j

Figure 8 is a plan view of the same embodiment, some parts being shown in section by a horizontal plane;

Figure 9 shows a section on the line IX-IX in Figure 7;

Figure 10 a section on the line X-X in Figure 7;

Figure 1l a section on the line XI--XI in Figure, 7;

- and Figure l2 a detail on a larger scale.

The press according to the iirst embodiment comprises a stationary, bolster abutmentor counter-holder 1, with a cavity 2, in the neighborhood of which the die 3 is arranged. Against the abutment 1 and the die 3 'bears the container 4, which slides with claws 5 upon two slideways 6a on guide bodies 6. The guide bodies 6 bearat one end against the bolster 1 and at the other end against a mounting 7 on the extrusion cylinder 3 of the press. Through each of the guide bodies passes a tie-rod 9, which bears in the usual way with a shoulder 10 against the abutment 1, and penetrates through the latter with a thinner anchoring portion 11. On the other side of the abutment 1 itis secured with a screw nut 12'. Two further tie-rods 13 connect the upper region of the abutment 1 with the mounting 7 of the extrusion cylinder 8.

The container 4 is seated in amounting 14, which has upper arms i5 and lower arms 16. To these arms upper container rods 17 and lower container rods 19 are secured by means of nuts 18. These container rods 17 and 19 pass with clearance through holes bored in the cross-head 20, and at their right-hand ends (in Figure l) are secured to the sliding cross-bar 21 by means of nuts 22. The cross-bar 21 slides in its turn with claws 23 upon the slideways da, and is rigidly connected with the container-holder 14 by the container rods 17 and 19. To the sliding cross-bar 2l are secured, by means of nuts 2S, two lateral plungers 24, which each extend into a cylinder 26, whichV is likewise-held by the mounting 7 of the extrusion cylinder 8. Attached to 4the sliding cross-bar 21 are also two pairs of crossbar rods 27, these being fastened by means of nuts 28. The cross-bar rods j sure into the cylinders 26, so that this pressureliqud' acts upon the plungers 24, which are connected fastV with The retraction of the slidingL cross-bar 21 is etected by admitting liquid under pressure into the cylinders 31, so that the pressure acts upon the plungers 30 and pushes the two vertical end crossbars 29 rearwards, towards the right, so that these end cross bars, through the medium of the cross-bar rods 27, pull the sliding cross-bar 21 towards the right. The cross-head 20 likewise slides with claws upon the guideways 6a, and carries the front end 33 of the press plunger 32, which moves forward in the extrusion cylinder 8 when liquid under pressure is admitted into the rear end of the extrusion cylinder. The forward displacement of the cross-head 20 is therefore effected byy the press plunger 32, whereas its retraction is effected by means of rods 34, which at their ends each carry a retraction plunger 35, which extends into a retraction cylinder 36, which is likewise carriedby the mounting 7 of the extrusion cylinder 8. Upon the admission of liquid under pressure into the retraction cylinders 36 the cross-head A20 is therefore drawn back towards the right by means of can be moved to and fro from the right in the axial direc-` tion of the press in a known manner which is not illustrated or further described. The means serving for this movement may for instance consist of a piston which is reciprocated in a stationary hydraulic cylinder.V

The cross-head 20 rigidly connected with the press ,plunger'32 is reliably guided straight, that is, always at right angles to the extrusion axis, since the press plunger 32 is always accurately guidedin and by the extrusion cylinder 8, and more particularly by means of its rear extension 38. This invention therefore employs the crosshead 20 for the adjustment or alignment of the container 4 before vthe extrusion begins. This is effected by retracting the cross-head 20, that is to say, moving it towards the right through a few millimeters, relatively to the position shown in the drawing. The sliding crossbar 21 is then moved to the left by means of the plungers 2 4 into contact with the cross-head 20, where it bears with its adjusting surface 21a against a corresponding adjusting surface 28a of thecross-head. When the sliding cross-bar 21 has in this way been constrained to assume a position which is exactly perpendicular to the extrusion axis, then the container 4 isV also correctly adjusted, sinceit is rigidly connected bythe four container rods 17 and 19 with the sliding cross-bar Z1. It is therefore not possible for the axis of the container 4 to be inclined at all to the extrusion axis.

If the press plunger 32 together with the cross-head 20, and the sliding cross-bar 21 together with the container 4, arenow collectively advanced through the remaining distance of a few millimeters, the exactly central position ofl the sliding cross-bar 21, with the container 4, is ensured. In yorder that with this advance the contact at the rectifying surfaces 20a and 21a may be maintained, the sliding cross-bar 21 is pushed forward with a force which is greater than the force that tends to push the press plunger 32 back, that is, towards the right, together with the cross-beam 20. This is attained by the fact that the cross-sectional area of the two plungers 24 that tend to advance the sliding cross-bar 21,7with the container 4, is made somewhatY greater than the effective cross-sectional area of the two retracting plungers 35, which seek to move the press plunger 35 rearwards. The full extrusion pressure may therefore be admitted to the retracting cylinders 36 to act upon the retracting plungers 35, since the force thereby produced is overcome by the greater thrust that is exerted by the pressure liquid in the 4 cylinders 31 upon the plungers 24 of the sliding crossbar 21.

It is thus ensured that the container 4 will be exactly concentric with the die 3 and the abutment 1; and since the mandrel 40 is iirmly guided in the press ram 37 and in the press plunger 32 it is now also ensured that the mandrel 40, as itV advances, will alsoY be exactly concentric with the bore of the receiver 4, and, after it has pierced a billet located in the bore of the receiver 4, will enter exactly centrally into the die 3. If' the mandrel 40 is exactly central in relation to the die 3, then, during the extrusion of the billet by means of the press ram 37, a tube is extruded which is of exactly the same wall thickness on all sides. i

The constructional example illustrated in Figures 6 to l2 is distinguished from the first embodiment, illustrated in Figures l to 5, by the fact that the sliding cross-bar, which in the first embodiment is arranged between the cross-head 26 and the extrusion cylinder 8, is now transferred to a position behind the extrusion cylinder. For the purpose of providing an adjusting surface against which the sliding cross-bar can be supported relatively to the cross-head, the sliding cross-bar is provided with rods which extend in a forward direction right into the neighborhood of the cross-head. This is illustrated in Figures 6 to 12. In the absence'of special indications to the contrary in the following description, the construction in Figures 6 to l2 corresponds to that already described in connection with the lirst embodiment.

Here again the abutment or counter-holder 51 is connected by tie-rods 52 with the mounting 53 of the extrusion cylinder 54. The cross-head 56, which carries the front end of the press plunger 57, and the container 58, slide upon two slideways 55. The press plunger 57 has a rear extension 59, whichV is attached to a retraction cross-bar 60. This retraction cross-bar 60 is equipped with retraction plungers 61, which extend into retraction cylinders 62, and effect the rearward movement of the press plunger 57 when liquid under pressure is admitted into the retraction cylinders 62. Upon the rear extension 59 of the press plunger 57 slides the sliding cross-bar 63, which is furthermore guided by its lower end 63a upon a guide rail 64. For the purpose of movement the sliding cross-bar 63 is provided with two sets of plungers 65 and 66. The plungers 65 act on one side of the cross-bar 63V and the plungers 66 act on the other side. The plungers 65 extend into cylinders 67 for retracting the sliding cross-bar 63, while the plungers 66 extend into forward cylinders 68. When liquid under pressure is admitted intd the two retraction cylinders 67, the sliding cross-bar 63 is moved back. When on the other'hand liquid under pressureis admitted into the forward cylinders 68, theY 73 bored in the crosshead 56. At the transition point Y from the diameter of the rods 71 to the diameter of the extensions 72 there is therefore a shoulder 74. The shoulders of the four rods 71 collectively form the adjusting surface for the container 58 as they come into contact with a corresponding adjusting surface 75 onrthe crosshead 56, when the sliding cross-bar 63 is moved forward.

The procedure with this second example of construction is also suchthat the press plunger 57, with its cross-head 56, is first brought into a position located a few millime- .ters to' the right of the position shown. Thereupon the sliding cross-bar 63, which is rigidly connected by the rods 72, 71 with the container 58, is moved forward until thel shoulders 74 strike against the corresponding .adjusting` surface 75 of the cross-head 56. The subsequent procedure may then be the same as has been described in connection with the rst embodiment.

The plunger cylinders are controlled by cocks connected by piping in the usual way with a hydraulic accumulato'r and with a waste pipe.

We claim:

1. A press for the extrusion of hollow products, comprising: a piercing mandrel, a cross-head, a press ram carried by the cross-head, a sliding cross-bar arranged behind the cross-head, a longitudinally displaceable container rigidly connected with the sliding cross-bar, an adjusting surface on the cross-head, and an adjusting surface on the sliding cross-bar, these adjusting surfaces being adapted to' be pressed together for the purpose of adjusting the sliding cross-bar, and with it the container.

2. An extrusion press as claimed in claim l, characterised by the feature that the sum of the crosssectional areas of plungers urging the sliding cross-bar forward is greater than the sum of the eective cross-sectional areas of plungers tending to retract the cross-head, with the result that the forward thrusts that can be caused to act upon the sliding cross-bar are greater than the rearward thrusts that can be caused to' act upon the cross-head, so that while the sliding cross-bar pushes the cross-head forward, the adjusting surface of the cross-head is pressed hard against the adjusting surface of the sliding cross-bar.

3. An extrusion press as claimed in claim 1, characterised by the feature that the sliding cross-bar is arranged behind the extrusion cylinder, the press further comprising cross-bar rods, which are guided past or through the extrusion cylinder, shoulders on the said cross-bar rods, near the front ends thereof, the front surfaces of these shoulders constituting the adjusting surface for the cross-head.

4. An extrusion press as claimed in claim 3, characterised by the feature that the cross-bar rods are rigidly connected with the sliding cross-bar, and include integral extensions extending through the cross-head, the other ends of these extensions being rigidly connected with the container.

References Cited in the le of this patent UNITED STATES PATENTS 1,317,238 Summey Sept. 30, 1919 2,142,704 Sparks Jan. 3, 1939 2,713,941 Schuler July 26, 1955 2,728,453 Thweatt et al Dec. 27, 1955 2,778,495 Krause Ian. 22, 1957 FOREIGN PATENTS 131,181 Great Britain Aug. 2l, 1919 536,729 Germany Oct. 27, 1931 629,573 Great Britain Sept. 22, 1949 

